B. S. Raghavendra and  D. Narayana Dutt,  Nonlinear Dynamical Characterization of Heart Rate Variability Time Series of Meditation.   journal   = {International Journal of Biomedical and Biological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2011, vol. 57(9). 429 - 440
    [viewed 24 April 2024]. Available from: https://publications.waset.org/pdf/1856.